By the end of this week’s G-20 summit in Russia, President Barack Obama may be wishing he’d backed out when he had the chance.

Russian President Vladimir Putin will have the opportunity to use the high-profile international meeting to try to diminish his U.S. counterpart by highlighting the lackluster support among world leaders for Obama’s plan to take military action against Syria’s government over its alleged use of chemical weapons.

Obama will face the delicate task of trying to paint Putin as an obstacle to justice in Syria, without picking fights with other countries that have expressed skepticism about a military response to the chemical weapons attack.

The timing of the looming G-20 meeting is, to say the least, awkward and uncomfortable for the White House.

Just a week ago, it looked like a U.S. military strike might be a fait accompli by the time the summit kicked off in St. Petersburg on Thursday. But the planned strike is now in a kind of limbo as Obama’s surprise request for Congress to bless military action is being thrashed out on Capitol Hill, with no assurance a use-of-force resolution will prevail and no final House or Senate vote expected before next week at the earliest.

The optics of the G-20 also have the potential to be tricky for Obama. The meeting takes the president out of the country and into the company of world leaders as some lawmakers are urging Obama to deliver an Oval Office address on Syria to explain, in part, why America should act in a case where so many other nations will not.

“This whole trip has become a total headache,” said Andrew Weiss, a National Security Council staffer under Presidents George H.W. Bush and Bill Clinton. “The dynamic is, Putin wants a public forum to put pressure on the president to make the president feel isolated….[Putin] is going to go even further, to try to use the G-20 meeting to create a kind of international referendum on possible military intervention in Syria.”

In public statements in advance of the meeting, Putin seemed eager to drag the Syria fight to center stage, while U.S. officials signaled that they’d rather keep the summit’s focus on the traditional stable of economic issues like stimulating growth, bolstering trade, and improving financial regulation.

Just hours after top Russian planners for the G-20 said they didn’t expect Syria to be part of the talks, Putin publicly countermanded them, telling reporters on Saturday the international meeting was a good chance to hash out the thorny issue.

“The G-20 is not a formal legal authority. It cannot act as a substitute platform for the UN Security Council, the only one able to authorize the use of force,” Putin said. “But it is a good platform to discuss the problem. Why not take advantage of it?”

By contrast, a senior U.S. official speaking during a pre-trip briefing last week tried to maintain emphasis on the economy.

Syria “is going to be part of the discussions. But I think there’s a robust agenda of work to be done at the G-20, and leaders are going to be focused on that,” said the official, who spoke on condition of anonymity.

There’s no doubt that the Syria crisis adds a wild card to the G-20, which, like most multilateral international summits, has become a highly scripted affair. Typically, all the critical decisions are ironed out in advance by underlings and there are few opportunities for leaders other than the host to speak publicly during official summit meetings.

That often works to the White House’s advantage by limiting surprises and confining the agenda to economic issues.

However, the careful stage-management means the host country enjoys more control over the mechanics of the event, which could allow Putin to take some shots at Obama over Syria without the U.S. president necessarily having an immediate chance to respond. He can, of course, offer a rebuttal during bilateral meetings the U.S. has announced with Chinese President Xi Jinping, French President Francois Hollande and Japanese Prime Minister Shinzo Abe.

Leaders do sometimes call an audible at such summits, seeking to use the international media presence to draw attention to subjects not on the official agenda.

During a G-20 summit meeting in Pittsburgh in 2009, Obama joined with French Prime Minister Nicolas Sarkozy and British Prime Minister Gordon Brown for a hastily-arranged morning statement seeking to up the pressure on Iran to abandon its nuclear program after the country admitted to a previously-undeclared nuclear fuel facility buried in a mountainside.

Some analysts said they expect Putin to try to use the Syria issue to boost the appearance that Russia is an indispensable player on the diplomatic scene, but to stop short of actions that could completely derail the G-20 over the carnage in Syria.

“Vladimir Putin’s first goal is a successful G-20 summit,” said Heather Conley of the Center for Strategic and International Studies. “I think some of the mixed messages coming from him in recent days is him teetering on not wanting this to be a poor reflection on his leadership on global economics.”

“Putin’s goal will be to demonstrate that, contrary to the Obama administration…. Russia is a serious power that cannot be neglected and carries real weight in the international community — that Russia remains a major player, and if Obama makes a decision to ignore Russia it isolates Obama more than isolating Putin,” said Dmitri Simes of the Center for the National Interest.

Among the countries attending the summit, only a few — like France and Turkey — seem to be strongly behind the idea of a military strike against Syria. But a complexity for Putin is that many G-20 nations that harbor doubts about the wisdom of strikes are also wary of Putin and of friction with the U.S.

“Most powers taking place in this summit are not exactly Putin’s friends,” Simes noted, pointing to the expected presence in St. Petersburg of U.S. allies like Germany, Canada, Australia and Mexico.

Earlier this summer, as the U.S. found itself locked in a dispute with Russia over National Security Agency leaker Edward Snowden, some lawmakers urged Obama to cancel his trip to the G-20, and perhaps even pull the U.S. out of the Winter Olympics set to take place in the Russian resort town of Sochi next year.

Obama instead chose a middle ground: scuttling a one-on-one summit with Putin in Moscow planned to precede the G-20 meeting.

Now, the Snowden fight has been eclipsed by the focus on Syria’s alleged use of chemical weapons and Russia’s longtime backing for Assad’s government.

However, Obama is still under political pressure at home to turn up the heat on Putin for defending Assad.

“We have not done enough to demonstrate that Russia has essentially become a pariah nation by being pro-chemical weapons,” Sen. Tim Kaine (D-Va.) said at a Foreign Relations Committee hearing Tuesday. “We should make them aware [of] being a pro-chemical weapons nation like a rotting carcass around their neck in every instance we can….We should make it painful every day.”

But Secretary of State John Kerry warned at the same hearing that going too far in publicly skewering the Russians over Syria could be counterproductive.

“I think it’s important for us not to get into an unnecessary struggle over some of this, for a lot of reasons,” Kerry said. “The Russians are working with us and cooperating on this effort to try to make this negotiated process [to resolve the Syria crisis] work, and I think they’re serious about trying to find a way forward with that,” he said, also noting potential threats to U.S.-Russian cooperation on nuclear arms reductions, Iran and North Korea.

While Obama seems unlikely to go as far as some U.S. lawmakers would like when it comes to confronting Russia, the American president does have some plans to tweak Putin.

Obama has set a meeting Thursday with dissidents, including gay and lesbian activists who are battling a Russian government crackdown including a law against spreading “propaganda” deemed to promote homosexuality.

Especially given calls by some gay activists for a boycott of the Olympics over the issue, Obama’s meeting with gay leaders struck some analysts as provocative.

”This is pretty unprecedented,” said Weiss, now with the Carnegie Endowment for International Peace. “It is, in many respects, an ‘in your face’ move.”

In an interview Tuesday with the Associated Press and a Russian TV outlet, Putin insisted he was untroubled by Obama’s plan to meet gay activists. The Russian leader said he’d even consider meeting with a similar group.

Putin also seemed to soften his tone in the latest interview, insisting there is no personal animosity between him and Obama.

“We work, we argue about some issues. We are human. Sometimes one of us gets vexed,” the Russian leader told the AP. “There are some gestures, of course, that you can only interpret one way, but no one has ever seen those kinds of gestures directed by Obama at me or by me at Obama, and I hope that never happens.”

Despite White House desires to play down the Syria angle to the upcoming meeting, there were indications this week — even from close U.S. allies — that the crisis in Syria could take center stage at the G-20.

Canada’s government announced Tuesday that Foreign Minister John Baird will fly to St. Petersburg specifically to handle discussions about Syria.

“The minister will be going to continue to engage with his counterparts on the situation in Syria,” a foreign ministry spokesman told Canadian news outlets.

Whether the White House likes it or not, it now seems inevitable that almost every event related to Obama’s trip will be seen through the prism of Syria.

Any interaction between Obama and British Prime Minister David Cameron will offer a reminder that the British Parliament rejected his call for action in Syria — underscoring the prospect that the U.S. Congress will pose a similar obstacle.

A scheduled bilateral meeting between Obama and China’s Xi will produce uncomfortable questions about why U.S. officials heap so much public scorn on Russia for its obstruction of U.N. resolutions condemning Syria, while taking a far more muted approach to China’s vetoes of the same resolutions.

Even a visit Obama made to a Jewish Synagogue and a Holocaust memorial during a pre-G-20 stop in Sweden Wednesday is likely to provoke discussion about the endorsement American Jewish groups gave Tuesday to action against Syria and how the administration is using dangers to Israel to make the case for a strike.

Obama himself hinted at such arguments during a press conference in Stockholm Wednesday, saying, “The people of Europe are certainly familiar with what happens when the international community finds excuses not to act.”

Still, for many analysts, any direct interaction between Putin and Obama will be among the most closely scrutinized moments of the G-20. With no formal one-on-one meeting planned between the two men, experts may be reduced to assessing the meaning of all sorts of ancillary events and random encounters.

“It’s now not about what happens at the official meetings and the economic agenda, but about hallway conversaitons and the press statements that will be flying,” said Conley, a former State Department official handling European affairs. “All of us will be fascinated even with the family photo at the G-20 to see just how far Putin and Obama are standing from each other.”